In the recent past, many advances have been made to reduce the invasiveness of cardiac surgery. In an attempt to avoid open, stopped-heart procedures, which may be accompanied by high patient morbidity and mortality, many devices and methods have been developed for performing surgery on a heart through smaller incisions, operating on a beating heart, and finally, in the past years, performing cardiac procedures via transvascular access. Significant technological advances have been made in various types of cardiac procedures, such as cardiac ablation techniques for treating atrial stenting procedures for atherosclerosis, and valve repair procedures. More specifically, much progress has been made on treating conditions such as mitral valve regurgitation. In implementing many minimally invasive cardiac surgery techniques, especially beating-heart techniques, one of the most significant challenges is positioning a treatment device and once positioned, to effectively deploy and fix a given device or treatment into or on the surface of the target cardiac tissue.
Traditional treatment of heart valve stenosis or regurgitation, such as mitral or tricuspid regurgitation, typically involves an open-heart surgical procedure to replace or repair the valve. Valve repair procedures typically involve annuloplasty, a set of techniques designed to restore the valve annulus shape and strengthen the annulus. Conventional annuloplasty surgery generally requires a thoracotomy, and sometimes a median sternotomy. These open heart procedures involve placing the patient on a cardiopulmonary bypass machine for sustained periods so that the patient's heart and lungs can be artificially stopped during the procedure. Finally, valve repair and replacement procedures are technically challenging and require a relatively large incision through the wall of the heart to access the valve.
Due to the highly invasive nature of open heart valve repair or replacement, high risk patients are usually not candidates for these procedures and thus are destined to functional deterioration and cardiac enlargement. Often, such patients have no feasible alternative treatments for their heart valve conditions.
In order to try and solve this problem, a number of devices and methods for repairing cardiac valves in a less invasive manner have been described. Some devices offer heart valve repair through minimally invasive incisions or intravascularly, while others attempt to improve open heart surgical procedures on beating hearts, stopped hearts or both. Difficulties in performing minimally invasive intra-cardiac surgery include positioning a minimally invasive treatment device in a desired location for performing a procedure and effectively placing and fixing a device into or on the surface of the target cardiac tissue. In heart valve repair procedures, for example, it is often essential for a physician to fix a device to valve annulus tissue. Annular tissue tends to be more fibrous than surrounding muscular or valve leaflet tissue, thus providing a more suitable location for securing such a device. In the past, various types of anchors and anchoring techniques have been developed in order to fix treatment devices to the annular tissue. This is an important stage in all annuloplasty procedures and especially in procedures for treating mitral or tricuspid valve regurgitation.
Devices and methods that address these difficulties are described in U.S. patent application Ser. Nos. 60/445,890, 60/459,735, 60/462,502, 60/524,622, 10/461,043, 10/656,797 and Ser. No. 10/741,130. For example, these references describe devices and methods for exposing, stabilizing and/or performing procedure on a heart valve annulus, such as a mitral valve annulus. Many of these methods and devices have shown preliminary promise, however a highly safe and effective method and engaging apparatus for performing cardiac valve annuloplasty has, until now, been lacking.